Engine



(No Model.) '3 Sheets-Sheet 1.

M. W. HALL.

STEAM ENGINE. No. 255,854. Patented App l, 188.2.

INVENTORZ ATTEsT:

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M. W. HALL.

(No Model.)

3 Sheets-Sheet 2r STEAM ENGINE.

Patented Apr. 4.18 82.

INVENTCIRZ A' TESTZ m UNITED STATES PATENT O FICE.

MILAN W. HALL, OF PLAINFIELD, NEW JERSEY, ASSIGNOR OF ONE-HALF TO ALBERTE. HALL, OF SAME PLACE. I

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 255,854, dated April 4,1882.

Application filed February 5, 1881.

To all whom it may concern Be it known that I, MILAN W. HALL, a citizenof the United States, residing in Plainfield,Union county, New Jersey,have invented certain Improvements in Steam-Engines, of which thefollowing is a specification.

This invention relates to thatclassof engines which employ twooylinders,the piston in one cylinder operating the valve which controls theadmission of steam to the other cylinder.

The-novel features consist partly in the construction and arrangement ofthe valves, ports, &c., and partly in the construction and arrangementof the reversing mechanism.

In the drawings, which serve to illustrate my invention, Figure l is asectional plan, the cylinders, valve-chest, &c., being in horizontalsection in the plane of the line a; a: in Fig. 3. Fig. 2 is a frontelevation of the engine from in front of the cross-heads. Fig. 3 is acrosssection of the engine, taken in the plane'of the line 3 y in Figs].Fig. 4 is a plan of the valve detached. Fig. 5is a detached sectionalview on line a 2, Fig. 3, arranged to illustrate the reversingmechanism. Fig. 6 is a sectional plan arranged to illustrate my improvedengine without the reversing mechanism, as applied direct.

Beferring to the first five figures of thedrawings, A A are twincylinders, provided with the usual pistons, B B, piston-rodsOO,orossheads D D, cross-head guides E E,suitable connecting-rods, and.cranks F F, fixed at right angles to each other on shaft Gr.

His asteam-chest, arranged to receive steam in the usual manner througha pipe, I. This steam-chest is arranged for convenience between thecylinders, and is employed in common for the valves in both engines. Itmight, however, be divided by a partition into two chests, and each bearranged to receive steam independently of the other.

J J are the valves, which operate generally as ordinary slide-valves,but have some peculiarities of construction and arrangement. Thesevalves are connected by means of rods a a. with arms K K, which projectinwardly from the cross-heads D D. It will be seen that the arrangementis such that the valve which controls the ports of one engine is (Nomodel.)

moved or shifted by the movement of the piston in the other, and thatthe valve-stroke equals the piston-stroke, the two being cou pledindirectly together. The valve is long and narrow, and the ports b I) bin the cylinders are also long and narrow to correspond, their form andarrangement in this particular being precisely the reverse of that inother engines as ordinarily constructed.

L L are what I denominate port-plates, whichare interposed between thevalves and the ports. These are supplied with ports or apertures c c andpassages which form a means ot'communication between the ports in thecylinder, and the valveand steam-chest. The portplates are arranged toform seats for the valves, and play vertically whenthe engines are to bereversed, as will be described.

In Fig 1, I have shown the steamports I) 1) arranged to open directlyinto the cylinders in both engines; but it is necessary in myarrangementthat these ports should be crossed in one engine-that is,thatthe portuncovered at the out end of the cylinder shall admit steam tothe in end, and vice versa. This will be obvious without furtherexplanation. To accomplish this result, however, I cross the ports orport-passages in the port-plate instead, as the preferable construction,as indicated by the dotted lines in Fig. 5.

I have shown the piston B at half-stroke and moving in the direction ofthe arrow, and the piston B at the end of its out-stroke and ready toreturn. The first movement of the piston B beyond the halfstroke willcarry forward the valve J of cylinder A and uncover an inlet-port, c, inthe port-plate, which admits steam (through a port, 0, in the cylinder)in front of the piston B and starts it back on 1 its return-stroke. Inmoving back it carries back the valve J of the other cylinder, and

when the piston B reaches the end of its outstroke, the piston B willhave reached the middle of its stroke, and carried the valve J farenough to uncover the port and admit steam in front of piston B. Thuseach piston in its travel alternately opens and closes the ports of thecylinder adjacent, and the valves travel the same distance as thepistons, and are coupled rigidly but indirectly to them.

Referring to Figs. 3 and 5, I will now describe the mechanism forreversing the engines.

The port-plates L L are arranged to slide up and down in theslide-chests M M, connected with the steam-chest. Only one of theseport-plates, L, is shown in Fig. 5 but it will be understood byreference to Figs. 1 and 3 that the crossed ports a c in the 'plate Lare arranged above the plain ports c; or it may be assumed that theplate L is precisely like the plate L, but inverted in position, so thatwhen both plates are down, as in Fig. 3, the plain ports in L willcoincide with the cylinder-ports, while in L the cross-ports will socoincide.

To the port-plates are aflixed stems N N, by which they can be moved upand down, and these stemsmay be yoked together, as in Fig. 3, so thatthey can be operated simultaneously by one stem or rod 0. I have notshown any mechanism for operating the port-plates, and any means may beemployed. WVhen the engines are to be reversed the port-plates aresimultaneously lifted until the lower ports in each plate are brought tocoincide with the cylinder-ports, and as this shifts the crossed portsfrom one engine to the other, as will be readily understood, theconditions otadmission of steam will be reversed and the shaft G will berotated in the opposite direction.

In lieu of shifting the port-plates vertically, I may arrange them to bemoved horizontally; or they might be madein theform of segments orquadrants and arranged to turn on an axis. The main point is to shiftthe crossed ports from one side to the other.

Instead of arranging the valves in the same horizontal plane and causingthe arms K K to lap past each other and arch over the valvestems, I mayset the valves in the same vertical plane, one above the other, andarrange the ports and passages to suit; orI may even arrange the valvesin different horizontal planes, but not in the same vertical plane.

The cylinders may be set in a vertical, horizontal, or inclinedposition.

In Fig. 6 I have shown my improved engine applied directly to a pumpwithout the intervention of a rotative mechanism In this construetionthe piston-rods are not connected in any way, and the reversingmechanism is omitted. Otherwise the construction is the same as thatshown in Fig. 1, except that the ports or port-passages in the cylinderA are crossed, for obvious reasons.

As my valve is narrow, it will be found that notwithstanding its unusuallength it has little more area for the steam to press on than theordinary slide-valve; and to lessen the area of pressure still more Iraise the seat of the valve slightly, so that when the valve passes itscentral position over the ports the laps at its ends pass out beyond theseat, so that the steam may get beneath them, and thus relieve thepressure.

. I am aware that it is not new to operate the valve controlling theadmission of steam to one cylinder by the piston which plays in theadjacent cylinder, and'that sliding port-plates for reversing are not,broadly considered, new; but I am not aware that my herein-describedconstruction and arrangement of these parts has ever before been knownor used.

Having thus described my invention, I claim--- 1. Asteam or other engineemploying a slidevalve and the usual inlet and exhaust ports, in whichthe valve has a strokeequal in length to the piston,and the longest axisof the portopening under the valve is in the plane of travel ofthevalve, substantially as set forth.

2. The combination, with the two cylinders and their pistons, rods,cranks, common shaft, and valves, actuated as shown, of the twoportplates L L, yoked together and arranged to be shiftedsimultaneously, said port-plates being provided with one set of plainand one set of crossed ports, arranged inversely in the two plates,whereby, when the plates are shifted, the crossed ports of one platewill be brought into play and those of the other plate thrown out,substantially as and for the purposes set forth. I

3. In a duplex engine, the combination of two steamcylinders, oneprovided with direct steam-ports, and the other with crossed steamports,two slide-valves controlling said ports, two piston-rods, and-mechanismconnecting the piston-rod of each engine with the valve of the oppositeengine, for moving said valves in the same direction as saidpiston-rods, substantially as specified.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

MILAN W. HALL. Witnesses:

HENRY CONNETT, GEO. BAINTON.

